Designing from the outside in

04/27/05

...extracting a re-usable framework after the fact struck me as interesting because that's really what's happened with Leonardo. Two years ago, I wrote a little wiki-like script in Python in order to enable editing of content on jtauber.com from a browser. I then decided to expand it just over a year ago to include a blog. Now, as more features are being requested, an underlying web framework is emerging that could very well be useful outside of running a wiki or blog.

The same thing happened with Cation (a web framework) and Dejavu (an ORM). I was tasked with rewriting our core business app—two years ago, it was a procedural CGI app written in Visual Basic 4! When I rewrote the whole thing in Python, I started by isolating Cation+Dejavu into their own layer. After about six months I then separated Dejavu from Cation. In addition, I made a middle business-objects layer called "EnDue", which the final app, "Mission Control" is built on. There's also a wiki-like app called "Junct" which I built on top of Cation and Dejavu. So the tree currently looks like this:

[Cation] [Dejavu]
\ /
\ /
[EnDue][Junct]
|
|
[Mission Control]

I've also got "test apps" for Dejavu and EnDue (well, I'm still writing the one for EnDue...I think I'll model the business of the beard-and-stone salesman from "Life of Brian" Any good names for such a business?).

Anyway, the real point I want to make (and have made before) is that I'll probably replace Cation with another web framework sometime this year...but I wouldn't have known which existing framework to pick if I hadn't written my own first.